In the paper processing or cardboard processing industry, such unwinding devices are used to withdraw one or more paper webs or cardboard webs from one or more wound rolls and to feed them to a subsequent processing machine, e.g. a transverse cutting machine. The wound rolls are held during the unwinding without a shaft between two guide heads clamping the wound roll between them and journaled on respective carrying arms. For loading the device with a new wound roll, for removing the roll residue and for adjustment to different rolls widths, the carrying arms with the guide heads are mounted so as to be movable toward and away from one another. In addition, the guide heads can be raised to lift a new wound roll from a receiving position on the floor to an unwinding position.
From German Utility Model G 85 11 986 an unwinding device of the aforedescribed type is known which has a transverse traverse on which the support beams are mounted so as to be transversely shiftable. The support beams are variable as to their lengths and carry the guide heads at their ends, the guide heads being insertable in the sleeve of a wound roll. The support beams are, in addition, swingable upwardly in order to provide a free space through which the device can be charged with a new wound roll from the side.
With the known unwinding devices it is necessary to position a new wound roll in the receiving position with relatively high accuracy so that the guide heads can be inserted into a sleeve in a problem-free manner. An excessive deviation from the setpoint position of the wound roll can lead to jamming of the guide heads during insertion. As a consequence, extensive aligning devices, (e.g. special lifting devices) are required to position the wound rolls with the requisite precision in their receiving positions in case the roll reception is to be effected automatically.